THE WORK FUNCTION IS THE ENERGY NEEDED TO REMOVE AN ELECTRON FROM A METAL SURFACE, SUCH AS IN THERMIONIC EMISSION. A LOWER WORK FUNCTION ALLOWS THE EMITTING SURFACE TO OPERATE AT A MUCH REDUCED TEMPERATURE FOR THE SAME CURRENT. LOW WORK FUNCTION SINGLE PHASE MATERIALS WITH REFRACTORY PROPERTIES ALLOW CATHODES TO OPERATE AT A LOWER TEMPERATURE AND SHOULD PERMIT LONGER LIFETIMES AT TEMPERATURES OF >1500C. THESE MATERIALS CAN BE FOR HIGH PERFORMANCE ARC-JET ENGINES AND ION THRUSTERS. THEY MAY ALSO FIND USE IN NEW TYPES OF VACUUM TUBES WHICH WOULD BE MORE EFFICIENT AND COMPACT. APPLICATION OF THIS TECHNOLOGY WOULD REVOLUTIONIZE HIGH POWER AMPLIFIERS, POWER SUPPLIES, AND MICROWAVE TRANSMISSION TECHNOLOGY.